255 research outputs found

    Models for the modern power grid

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    This article reviews different kinds of models for the electric power grid that can be used to understand the modern power system, the smart grid. From the physical network to abstract energy markets, we identify in the literature different aspects that co-determine the spatio-temporal multilayer dynamics of power system. We start our review by showing how the generation, transmission and distribution characteristics of the traditional power grids are already subject to complex behaviour appearing as a result of the the interplay between dynamics of the nodes and topology, namely synchronisation and cascade effects. When dealing with smart grids, the system complexity increases even more: on top of the physical network of power lines and controllable sources of electricity, the modernisation brings information networks, renewable intermittent generation, market liberalisation, prosumers, among other aspects. In this case, we forecast a dynamical co-evolution of the smart grid and other kind of networked systems that cannot be understood isolated. This review compiles recent results that model electric power grids as complex systems, going beyond pure technological aspects. From this perspective, we then indicate possible ways to incorporate the diverse co-evolving systems into the smart grid model using, for example, network theory and multi-agent simulation.Comment: Submitted to EPJ-ST Power Grids, May 201

    Efficacy of sorafenib, a multi-tyrosine kinase inhibitor, in an adenoid cystic carcinoma metastatic to the lung: case report and review of literature

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    <p>Abstract</p> <p>Introduction</p> <p>Treatment for squamous cell carcinoma of the head and neck has significantly improved with the addition of cetuximab, a monoclonal antibody against the epidermal growth factor receptor, to conventional cytotoxic agents. The most significant aspect of this treatment approach is the proof that head and neck cancers are suitable for targeted therapies as has been shown in other malignancies. Unfortunately, there are other rare histologic types of head and neck cancer such as adenocarcinoma and adenoid cystic carcinoma. The latter has traditionally been considered to be chemotherapy resistant and surgical resection with or without adjuvant radiation therapy has been the rule as far as treatment is concerned. The course of adenoid cystic carcinoma ranges from indolent to aggressive; however, most patients succumb to the disease as a result of distant metastases. This clinical scenario poses a challenge to oncologists. Several conventional chemotherapy regimens and novel targeted agents have been tried in this rare histologic subtype without success.</p> <p>Case presentation</p> <p>In this case report, we present a 59-year-old Caucasian female with refractory adenoid cystic carcinoma of the maxilla metastatic to the lung that responded to sorafenib, a novel multi-tyrosine kinase inhibitor, which targets angiogenesis, Raf kinase pathway, platelet-derived growth factor Ret, and c-Kit.</p> <p>Conclusion</p> <p>This case illustrates the possibility that this chemoresistant tumor may need the inhibition or blocking of several oncogenic pathways. Certainly, it is imperative that more studies are done in this special population trying to identify tumorigenesis mechanisms that may be upregulated in this malignancy and could be potential targets for therapeutic development.</p

    Immunotherapy of lung cancer: An update

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    In Germany lung cancer is the leading cause of cancer-associated death in men. Surgery, chemotherapy and radiation may enhance survival of patients suffering from lung cancer but the enhancement is typically transient and mostly absent with advanced disease; eventually more than 90% of lung cancer patients will die of disease. New approaches to the treatment of lung cancer are urgently needed. Immunotherapy may represent one new approach with low toxicity and high specificity but implementation has been a challenge because of the poor antigenic characterization of these tumors and their ability to escape immune responses. Several different immunotherapeutic treatment strategies have been developed. This review examines the current state of development and recent advances with respect to non-specific immune stimulation, cellular immunotherapy ( specific and non-specific), therapeutic cancer vaccines and gene therapy for lung cancer. The focus is primarily placed on immunotherapeutic cancer treatments that are already in clinical trial or well progressed in preclinical studies. Although there seems to be a promising future for immunotherapy in lung cancer, presently there is not standard immunotherapy available for clinical routine

    A Multicenter, Phase 2 Study of Vascular Endothelial Growth Factor Trap (Aflibercept) in Platinum- and Erlotinib-Resistant Adenocarcinoma of the Lung

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    IntroductionAflibercept (vascular endothelial growth factor [VEGF] trap), a recombinant fusion protein, blocks the activity of VEGF-A and placental growth factor and has demonstrated activity in pretreated patients with lung cancer in a phase I trial. This study evaluated the efficacy and safety of intravenous aflibercept in patients with platinum- and erlotinib-resistant lung adenocarcinoma.MethodsAn open-label, single arm, multicenter trial was conducted, with the primary end point of response rate (modified RECIST). Additional endpoints included safety, duration of response, progression-free survival, and overall survival. Patients with platinum- and erlotinib-resistant lung adenocarcinoma were eligible. Aflibercept 4.0 mg/kg intravenous every 2 weeks was administered until progression of disease or intolerable toxicity.ResultsNinety-eight patients were enrolled; 89 were evaluable for response. Median age was 60 years, 41% were men with Eastern Cooperative Oncology Group performance status 0/1/2 in 35/55/9% of patients. The overall response rate was 2.0%, (95% confidence interval, 0.2-7.2%). Median progression-free survival was 2.7 months, and overall was survival 6.2 months. Six- and 12-month survival rates were 54 and 29%, respectively. A median of four cycles was administered (range 1-22). Common grade 3/4 toxicities included dyspnea (21%), hypertension (23%), and proteinuria (10%). Two cases of grade 5 hemoptysis were reported, and one case each of tracheoesophageal fistula, decreased cardiac ejection fraction, cerebral ischemia, and reversible posterior leukoencephalopathy.ConclusionsAflibercept has minor single agent activity in heavily pretreated lung adenocarcinoma, and is well tolerated, with no unexpected toxicities. Further studies evaluating aflibercept in lung cancer, in combination with chemotherapy and other targeted therapies, are ongoing

    Primary Polyomavirus Infection, Not Reactivation, as the Cause of Trichodysplasia Spinulosa in Immunocompromised Patients

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    Classic human polyomaviruses (JC and BK viruses) become pathogenic when reactivating from latency. For the rare skin disease trichodysplasia spinulosa, we show that manifestations of the causative polyomavirus (TSPyV) occur during primary infection of the immunosuppressed host. High TSPyV loads in blood and cerebrospinal fluid, sometimes coinciding with cerebral lesions and neuroendocrine symptoms, marked the acute phase of trichodysplasia spinulosa, whereas initiation and maturation of TSPyV seroresponses occurred in the convalescent phase. TSPyV genomes lacked the rearrangements typical for reactivating polyomaviruses. These findings demonstrate the clinical importance of primary infection with this rapidly expanding group of human viruses and explain the rarity of some novel polyomavirus-associated diseases.Peer reviewe

    A New Lead Chemical for Strigolactone Biosynthesis Inhibitors

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    Several triazole-containing chemicals have previously been shown to act as efficient inhibitors of cytochrome P450 monooxygenases. To discover a strigolactone biosynthesis inhibitor, we screened a chemical library of triazole derivatives to find chemicals that induce tiller bud outgrowth of rice seedlings. We discovered a triazole-type chemical, TIS13 [2,2-dimethyl-7-phenoxy-4-(1H-1,2,4-triazol-1-yl)heptan-3-ol], which induced outgrowth of second tiller buds of wild-type seedlings, as observed for non-treated strigolactone-deficient d10 mutant seedlings. TIS13 treatment reduced strigolactone levels in both roots and root exudates in a concentration-dependent manner. Co-application of GR24, a synthetic strigolactone, with TIS13 canceled the TIS13-induced tiller bud outgrowth. Taken together, these results indicate that TIS13 inhibits strigolactone biosynthesis in rice seedlings. We propose that TIS13 is a new lead compound for the development of specific strigolactone biosynthesis inhibitors
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